<footer>
  <ul>
    <li>
      <%= Date.today.year %> © 
    </li>
    <li id="trade_mark">
      <%= link_to t('site.name'), 'http://social-stream.dit.upm.es/' %>
    </li>
    <li>
      <%= link_to(image_tag('HTML5.png'), 'http://validator.w3.org/check?uri=referer') %>
    </li>
    <li>
      <%= link_to(image_tag('HTML5_Styling.png'),'http://jigsaw.w3.org/css-validator/check/referer') %>
    </li>
    <li>
      <%= link_to(image_tag('HTML5_Semantics.png'),'http://jigsaw.w3.org/css-validator/check/referer') %>
    </li>
  </ul>
</footer>